中文摘要：

提出并研究了一种3自由度的多连杆正铲挖掘机机构，并运用D-H法对该挖掘机构进行运动学数学建模，得到铲斗位姿的正反解，模拟动臂提升和水平推压工况，分别得到提升状态下铲斗姿态角变化情况和水平推压过程中3组液压缸长度的关系。最后基于运动学正解和奇异判断条件在MATLAB平台上实现该多连杆正铲挖掘机构包络图的自动绘制，结果显示其挖掘范围满足工作要求。本研究为该机构的优化设计、动力学分析和控制系统的设计提供了基础。

英文摘要：

A new multi-linkage face-shovel excavator of 3-DoF is proposed and the position kinematics model is established using existing D-H method in this paper. The variation of bucket angle and the length of 3 cylinders of this mechanism are demonstrated respectively by simulating calculation of forward and inverse positions of the boom-lifting and level excavation. Finally, the digging envelope is automatically formed based on forward position kinematics and singularity identification program in MATLAB. It is shown that the digging ranges and shape of the mechanism are reasonable. The study will provide the basis for the optimization de-sign, dynamics analysis and control system of this mechanism.